Dozens of supporters, including Mayor Brown, gathered at Old County Hall for Sunday's ceremony.

Mark Poloncarz says he will serve as an independent monitor of the county's finances and conduct timely, proactive and thorough audits and reviews of the county's departments.

Poloncarz said, "I intend to shape the Office of the Comptroller's audit department into an inspector general-style organization that stops and prevents waste, fraud and abuse of county tax dollars."

Poloncarz is the first Democrat since the mid-1970s to serve as the county's fiscal watchdog.